Rejection type fuse clip



June 28, 1960 v W RT 2,943,295

REJECTION TYPE FUSE CLIP Filed Feb. 6, 1957 F Fig.2. /3

Inventor:

Vincent N. Stewart,

United States Patent f REJECTION TYPE FUSE CLIP Vincent N. Stewart,Springfield, Pa., assignor to General Electric Company, a corporation ofNew York Filed Feb. 6, 1957, Ser. No. 638,573

8 Claims. (Cl. 339--258) My invention relates to fuse clips forcartridge fuses and more particularly to fuse clips incorporating meansfor preventing insertion of improper fuses.

Fuse clips of the conventional type which include fierible clamping-armsfor receiving the end terminals of cartridge fuses have the inherentdisadvantage of being susceptible to the insertion of fuses havingcurrent-interrupting capacities different from the preferred fuse. Wltha view toward correcting this possibly dangerous situation, some priorfuse clips have been provided with rejection features, in the form ofinterference means, for resisting the insertion of such improper fuses.However, the interference means have been formed in the flexibleclamping arms of the fuse clip, and the arms, whileresisting theinsertion of an improper fuse, were susceptible to being overstressedduring attempted insertion. Moreover, in some cases, even with fuseclips which included interference means incorporated with flexibleclamping arms, improper fuses could be inserted, provided sufficientpressure was exerted on the fuse. My present invention incorporatesimproved rejection means, eliminating-the disadvantages of the prior artstructures.

It is an object ofmy invention to provide a fuse clip including animproved arrangement for insuring regection of improper fuses.

Another object of my invention. is to provide a fuse clip including animproved arrangement for preventing overstressing the flexible contactarms by attempted insertion of an improper fuse.

A further object of my invention is to provide a fuse clip including animproved means for insuring axial alignment of the fuse within the clip.

Furtherobjects and advantages of my invention Wlll become apparent asthe following description proceeds, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of the specification.

In accordance with one form of my invention, I provide a fuse cliphaving spaced generally-parallel flexible ams. These arms are providedwith aligned slots. An interference member, which is formed as a rigidelement separate from the clip itself, is mounted in these slots andextends transversely across the gap between the flexible arms to preventinsertion of improper fuses in the fuse clip. I

For a better understanding of my invention reference may be had to theaccompanying drawings in which Figure 1 is a perspective view of amounting clip and a specially grooved cartridge'type fuse embodying oneform of my invention. Figure 2 is also a perspective view of anotherembodiment of my invention. Figure 3 is an end view of the secondembodiment showing the fuse in operative position within the mountingclip.

Referring now to Figure 1 of the drawing, there is shown a fuse clip forengagement with an. appropriately dimensioned cartridge fuse, the fuseclip including an interference means for rejecting an improper fuse. Thefuse clip comprises a main body 1', preferably of a interference member5. The diameter 2,943,295 Patented June 28, 1960 highly conductivematerial such as copper, which includes a pair of upstanding, spaced,generally parallel, flexible arms 2. The arms 2 have outwardly curvedportions 3 defining opposing concave contact surfaces for engagingopposite sides of the ferrule or end terminal of a cartridge fuse. Thecurvature of the contact surfaces enables the flexible arms to contactas much of the cylindrical ferrule surface as possible, thereby insuringgood electrical con tact as well as aiding in the axial alignment of thefuse within the clip. The flexible clamping arms 2 are provided withaligned slots or openings 4 for positioning the transversely extending,relatively rigid interference member 5. The interference member has itsend portions 6 extending through the aligned slots 4, allowing freelateral movement of the flexible clamping arms with respect to thestationary interference member during insertion of the fuse within theclip. The bottom of the main body 1 of the fuse clip is adapted to berigidly connected or anchored to a conventional mounting block, notshown.

The interference member 5 is anchored in place with n the aligned slots4 of the flexible clamping arms by of ears 7 contacting the laterallyextending shoulder portions 3 of interference member 5. The ears 7 areformed from the material punched out of the flexible clamping arms 2 toprovide the aligned slots 4. This construction lends itself to arelatively economical method of anchoring the interference member withinthe main clip body.

The upper portion of interference member 5 has a centrally located,generally U-shaped opening therein for receiving a specially reducedportion of the cylindrical fuse ferrule 19. The cartridge fuse 11includes the cylindn'cal ferrule 10, which has a grooved portion 12 ofreduced diameter for engagement Within opening 9 of the of the ungroovedportion of the fuse ferrule it is larger than the width of the U-shapedopening 9 of the interference member, but the dimension across theferrule at the grooved portion 12 is sufficiently reduced to permit thefuse to be inserted within this opening. In other words, the specialrecess 12 is formed in the ferrule 19 to accommodate the interferencemember 5 upon insertion of a proper cartridge fuse 11 in the fuse clip.Since the U-shaped openings conforms to the curvature of the recessedportion of the fuse ferrule, the interference member engages the ferrulefor a full and is therefore effective to precisely limit the insertingmovement of the fuse to the desired position in the clip. Thus, theinterference mcmber cooperates with the flexible clamping arms forinsuring proper positioning and axial alignment of the fuse within theclip. More perfect alignment is therefore achieved by providing aninterference member which extends the whole distance, between theflexible clamping arms.

The present invention is also applicable to fuse clips for receivingfuses having blade-type terminals. For example, referring to theembodiment of Figs. 2 and 3, there is shown a somewhat modified form offuse clip comprising a main body 13 which includes a pair of upstanding,spaced, parallel, flexible arms 14. Unlike the previous clip member ofFigure l, the opposing contact surfaces 15 of the arms 14 are notcurved, but are flattened to conform to the rectangular end terminal ofthe cylindrical cartridge fuse 2G. The flexible clamping arms areprovided with aligned slots 16 for positioning the transverselyextending rigid interference member 17 in the same manner as theembodiment shown in Figure 1. However, the rigid interference member isattached to the floor portion of the main clip body by means such aswelding rather than by use of the inwardly extending ears integral withthe flexible clamping arm's in Figure 1. The interference member-d7 is"provided" with a on either side, which allows it to be inserted withinthis opening. Figure 3 illustrates the relationship of the parts afterthe properly configured fuse 20 has been fully inserted into the clip.

The interference element is a relatively rigid member preferably ofsteel, and is supported independently of the flexible clamping arms. Itforms the resisting element upon an attempted insertion of a fuse havingan end terminal of improper configuration and absorbs the full insertionforce. Previous fuse clip arrangements were of such a nature that theflexible clamping arms themselves acted as the resisting members, andinsertion of an improper fuse was still possible provided sufiicientpressure was exerted on the fuse. Moreover, the exertion of suchpressure could result in overstressing of the flexible clamping arms. Inthe present design, however, attempted insertion of a standard fuse,i.e., a fuse having an ungrooved ferrule and hence no special provisionfor accommodating the interference member, merely results in somelateral movement of the flexible clamping arms, with the interferencemember absorbing the insertion force and rejecting the fuse. Theinterference member acts to block such fuse insertion before the fusecan be moved to a point where it can be held by the flexible clampingarms. Thus, the flexible clamping arms may be designed to give idealperformance from the standpoint of providing a good electricalconnection with the fuse terminals without any compromise being neededin order to render them capable of withstanding the forces incident toinsertion of an improper fuse.

'While I have shown and described specific embodiments of my invention,I do not desire my invention to be limited to the particularconstruction shown and described and i intend by the appended claims tocover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A fuse clip comprising a main body member including spaced,generally-parallel flexible clamping arms hav 'ing opposing contactsurfaces for engaging opposite sides of the end terminal of a cartridgefuse, and a rigid interference member disposed between the opposingcontact surfaces of said clamping arms for preventing the insertion ofany cartridge fuse whose end terminal is not provided with a specialrecess arranged to accommodate said interference member.

2. A fuse clip comprising a main body member in cluding spaced,generally-parallel flexible clamping arms having opposing contactsurfaces for engaging opposite sides of the end terminal of a cartridgefuse inserted between said clampiug arms, said arms having openingstherein, and a rigid interference member received within said openingsand extending transversely between said clamping arms for permi ginsertion of only those carfridge fuses having end terminals of properconfiguration for accommodating said interference member, said openingsallowing free lateral movement of said clamping arms relative to saidinterference member.

3. A fuse clip comprising a main body member including spaced,generally-parallel flexible clamping arms,

said arms having aligned slots therein, and a rigid interference memberreceived within said slots and extending transversely between saidclamping arms for permitting only a properly configured fuse to beinserted in the fuse clip, said interference member having a pair oflaterally extending shoulder portions, said flexible clamping armsincluding integral inwardly extending ears, said ears being formed fromat least a portion of thematerial dis- 4 V placed from said clampingarms to form said aligned slots and said ears contacting said shoulderportions of said interference member for holding said interferencemember within said main body member.

4. A fuse clip comprising a main body member including spaced,generally-parallel flexible clamping arms having opposing contactsurfaces for engaging opposite sides of the end terminal of a cartridgefuse, and a rigid interference member transversely extending between theopposing contact surfaces of said clamping arms, said interferencemember including a generally U-shaped opening adapted to receive acooperating grooved portion of the end terminal of a proper cartridgefuse inserted in the fuse clip, said interference member being effectiveto reject any cartridge fuse having an end terminal the minimumdimension across which is greater than the maximum transverse dimensionof said opening.

5. A fuse clip comprising a main body including spaced,generally-parallel flexible clamping arms, said arms having openingstherein, and a rigid interference member received within said openingsand extending transversely 'between said clamping arms, saidinterference member including a generally U-shaped opening adapted toreceive a cooperating slotted rectangular fuse terminal.

6. A fuse clip' comprising a main body having a bottom adapted to berigidly connected to a mounting base and including a pair of spaced,flexible clamping arms, said flexible clamping arms having alignedslots, a relatively rigid interference member positioned between and atright angles to said flexible clamping arms, said interference memberhaving end portions positioned within and extending through said alignedslots in said flexible clamping arms allowing free lateral movement ofsaid flexible clamping arms with respect to said interference member,inwardly extending ears integral with said flexible clamping arms andengaging said interference membar for anchoring said interferencemember-to the bottom of said main body, a generally U-shaped centrallylocated opening in the upper portion of said interference member adaptedto receive a cooperating grooved cylindrical fuse ferrule. i

7. A fuse clip comprising a main body including a pair of spaced,flexible clamping arms, said flexible clamping arms having alignedslots, a relatively rigid interference member positioned between and atright angles to said flexible clamping arms, said interference memberhaving end portions positioned within and extending through said alignedslots in said flexible clamping arms, allowing free lateral movement ofsaid flexible clamping arms with respect to said interference member,inwardly extending ears integral withsaid flexible clamping arms andengaging said interference member for anchoring said interferencememberwithin said base member, a generally U-shaped centrally locatedopening in the upper portion of said interference member adapted toreceive a-cooperating grooved cylindrical fuse ferrule, said U-shapedopening of said interference member being adapted'to engageapproximately 180 of the grooved portion of the fuse ferrule, wherebyaxial alignment of the fuse within the clip is facilitated.

8. A fuse clip for a cartridge fuse comprising: a main body memberincluding spaced, generally-parallel flexible clamping arms havingopposing contact surfaces for engaging cooperating contact surfaces ofan end terminal of a cartridge fuse inserted between said clamping arms;

and a rigid, transversely-extending interference member disposedintermediate the opposing contact surfaces of said clamping arms, saidinterference member being provided with an opening adapted to receive aspecially reduced portion of the end terminal of said cartridge fusewhen inserted between said clamping arms. the maximum transversedimension of said opening being smaller than themaximum distancebetweensaid cooperating contact surfaces of the end terminal whereby saidinterference 5 6 member will reject an otherwise appropriately dimen-FOREIGN PATENTS sioned cartridge fuse whose end terminal is not pro-6031539 Great Britain June 17 1948 vided with said specially reducedportion. 841,302 Germany June 1952 References Cited in the file of thispatent 5 OTHER REFERENCES UNITED STATES PATENTS Page et a1., Abstract ofapplication Serial No. 193,380, 2,068,314, Dotterer June 19, 1937published March 24, 1953, 668, O. G. 1125.

